The invention relates to a spreader vehicle for solid, granulated, and liquid thawing materials which are taken out of separate vessels and supplied to impellers in quantities proportional to the speed of travel and adjustable to selectable scatter densities.
In all spreader vehicles and spreader implements known until now, which carry solid and liquid thawing materials simultaneously, the liquid thawing materials are not spread separately but are used only to moisten the solid thawing materials (e.g. German Pat. No. 1 936 564, German Pat. No. 2632 794, German OS No. 1 534 296, German OS No. 1 459 760, German AS No. 1 299 013, Swiss Pat. No. 516 050).
Devices are also known for spraying a thawing salt solution on traffic areas where a spray device with spray nozzles is mounted on a vehicle, to which the thawing salt solution is supplied by a liquid pump from a liquid tank carried by the vehicle. The thawing salt solution is delivered to the spray device in quantities which are adjustable as a function of travel speed. With this device, however, solid thawing materials cannot be scattered. In addition, it has been found in practice that spray nozzles, to which the liquid to be sprayed must be supplied will, at a relatively high pressure for a spraying effect to be obtained at all, cause too much nebulization of the liquid, so that such spray devices for the treatment of icy roads cannot be used on the one hand for reasons of environmental protection and on the other for reasons of thrift.
Spreader implements are also known (German Pat. No. 2 011 894) which can be placed on the loading platform of a vehicle and with which scatter substances different from one another, e.g. gravel and salt, can be scattered simultaneously or separately from each other and which comprises two separate vessels, each with a belt conveyor and a distributor plate. In addition, these spreader implements have a control device for the travel speed-dependent drive of the belt conveyor and for the setting of different constant drive speeds of the distributor plates. The drives of the belt conveyors and of the distributor plates of both vessels are adapted to be switched on singly or jontly. The two vessels and their belt conveyors are arranged in paralle, side by side in the direction of the longitudinal vehicle axis and are equipped with a distributor plate at the rear end of each belt conveyor. At least one of the plates are pivotable about an eccentric vertical axis and fixable into any desired position.
With these so-called double spreader implements only solid granulated scatter substances can be scattered. With the simultaneous use of both spreader devices, double the scatter width of a single spreader device can be obtained, so that also relatively wide roads can be covered in one spreading operation. However, the maximum attainable scatter width is only about 10 meters, this being attributable in particular to the fact that the two spreading devices are arranged close together and permit a spreading angle of at most 90.degree. if a homogeneous scatter densityiis to be ensured. Liquid thawing materials alone cannot be scattered with these known spreaders.